a. Field of Invention
This invention pertains to devices for introducing or removing fluids from a human body known as catheters and more particularly to a preformed catheter which has a very small diameter to be used in pediatric treatment.
b. Description of the Prior Art
Catheters for fluid injection into, or removal from a human body are well known in the art. They usually comprise a tubular body with a plurality of longitudinal bores having a distal end provided with several openings for the bore. One major problem with the catheters has been their tendency to migrate or to be expelled by the body. Various solutions have been proposed and used to solve this problem. For example some catheters have been made with sharply pointed barbs or flanges which are disposed on the outer surface of the catheter and which engage the side walls of the opening through which the catheter has been extended. However these barbs or flanges often irritate the tissues of the opening walls and may even damage them and cause serious injuries. Another approach is to provide an expandable member, such as a balloon, at the distal end of the catheter. A separate means for expanding the device must be included in the catheter, such as an inflation bore, which naturally increases its diameter. Therefore, this approach is unacceptable in certain types of operations where very thin catheters are needed, such as for example the catheters needed to drain the bladder of a four year old infant because the effective inner diameter of the bore through which drainage occurs is too small to be effective, especially if urinary salts deposit on the inner walls thereat during long term drainage. In addition the cost of making balloon-type catheters is relatively high.